Melt butter in heavy large deep skillet over high heat. Add squash and sauté for 1 minute. Add broth, syrup, cinnamon, salt, and pepper. Bring to boil, cover, reduce heat to medium, and cook until squash is almost tender, about 10 minutes. Using slotted spoon, transfer squash to large bowl. Boil liquid in skillet until thickened, 3 to 4 minutes. Return squash to pan and cook until tender, turning occasionally, another 5 minutes.